Using promises with $http

HTTP requests are the quintessential variable latency operations that demand a promise construct. Since it would appear that developers are stuck with the uncertainty stemming from TCP/IP for the foreseeable future, it behooves you to architect your applications to account for this.

How to do it…

The $http service methods return an AngularJS promise with some extra methods, success() and error(). These extra methods will return the same promise returned by the $http service, as opposed to .then(), which returns a new promise. This allows you to chain the methods as $http().success().then() and have the .success() and .then() promises attempt to resolve simultaneously.

The following two implementations are more or less identical, as everything is being chained upon the $http promise:

// Implementation #1
// $http.get() returns a promise
$http.get('/myUrl')
// .success() is an alias for the resolved handler
.success(function(data, status, headers, config, statusText)...